[virt-tools-list] [remote-viewer v1] remote-viewer: fix free on dangling pointer
Eduardo Lima (Etrunko)
etrunko at redhat.com
Fri Sep 27 19:21:58 UTC 2019
On 9/27/19 10:35 AM, Victor Toso wrote:
> From: Victor Toso <me at victortoso.com>
>
> On remote_viewer_session_connected() we are passing a dup of URI of
> connection and freeing it afterwards. Problem is, we don't disconnect
> from listening "session-connected" and on an eventual second emission
> of this signal, remote-viewer crashes as seen in the backtrace below.
>
> This can happen over switch-host migration message from
> SpiceMainChannel.
>
> To fix the issue, use VirtViewerApp URI information instead of passing
> a dup char*. The other changes in this patch were warnings of unused
> variables.
>
> Found it while improving migrate.py from spice/tests (server):
> | Invalid free() / delete / delete[] / realloc()
> | at 0x4839A0C: free (vg_replace_malloc.c:540)
> | by 0x56EBD8C: g_free (in /usr/lib64/libglib-2.0.so.0.6000.6)
> | by 0x11DED0: remote_viewer_session_connected (remote-viewer.c:658)
> | by 0x564D741: g_closure_invoke (in /usr/lib64/libgobject-2.0.so.0.6000.6)
> | by 0x56614F3: ??? (in /usr/lib64/libgobject-2.0.so.0.6000.6)
> | by 0x566A34D: g_signal_emit_valist (in /usr/lib64/libgobject-2.0.so.0.6000.6)
> | by 0x566AF68: g_signal_emit_by_name (in /usr/lib64/libgobject-2.0.so.0.6000.6)
> | by 0x135E5D: virt_viewer_session_spice_main_channel_event (virt-viewer-session-spice.c:699)
> | by 0x564D741: g_closure_invoke (in /usr/lib64/libgobject-2.0.so.0.6000.6)
> | by 0x56614F3: ??? (in /usr/lib64/libgobject-2.0.so.0.6000.6)
> | by 0x566A34D: g_signal_emit_valist (in /usr/lib64/libgobject-2.0.so.0.6000.6)
> | by 0x53149E3: emit_main_context (gio-coroutine.c:198)
> | Address 0x18f1ecc0 is 0 bytes inside a block of size 23 free'd
> | at 0x4839A0C: free (vg_replace_malloc.c:540)
> | by 0x56EBD8C: g_free (in /usr/lib64/libglib-2.0.so.0.6000.6)
> | by 0x11DED0: remote_viewer_session_connected (remote-viewer.c:658)
> | by 0x564D741: g_closure_invoke (in /usr/lib64/libgobject-2.0.so.0.6000.6)
> | by 0x56614F3: ??? (in /usr/lib64/libgobject-2.0.so.0.6000.6)
> | by 0x566A34D: g_signal_emit_valist (in /usr/lib64/libgobject-2.0.so.0.6000.6)
> | by 0x566AF68: g_signal_emit_by_name (in /usr/lib64/libgobject-2.0.so.0.6000.6)
> | by 0x135E5D: virt_viewer_session_spice_main_channel_event (virt-viewer-session-spice.c:699)
> | by 0x564D741: g_closure_invoke (in /usr/lib64/libgobject-2.0.so.0.6000.6)
> | by 0x56614F3: ??? (in /usr/lib64/libgobject-2.0.so.0.6000.6)
> | by 0x566A34D: g_signal_emit_valist (in /usr/lib64/libgobject-2.0.so.0.6000.6)
> | by 0x53149E3: emit_main_context (gio-coroutine.c:198)
> | Block was alloc'd at
> | at 0x483880B: malloc (vg_replace_malloc.c:309)
> | by 0x56EBC98: g_malloc (in /usr/lib64/libglib-2.0.so.0.6000.6)
> | by 0x5705C43: g_strdup (in /usr/lib64/libglib-2.0.so.0.6000.6)
> | by 0x11EB80: remote_viewer_initial_connect (remote-viewer.c:696)
> | by 0x11EB80: remote_viewer_start (remote-viewer.c:790)
> | by 0x1250D3: virt_viewer_app_start (virt-viewer-app.c:1727)
> | by 0x127108: virt_viewer_app_on_application_startup (virt-viewer-app.c:1870)
> | by 0x564D741: g_closure_invoke (in /usr/lib64/libgobject-2.0.so.0.6000.6)
> | by 0x5661638: ??? (in /usr/lib64/libgobject-2.0.so.0.6000.6)
> | by 0x566A34D: g_signal_emit_valist (in /usr/lib64/libgobject-2.0.so.0.6000.6)
> | by 0x566A972: g_signal_emit (in /usr/lib64/libgobject-2.0.so.0.6000.6)
> | by 0x553ECA1: g_application_register (in /usr/lib64/libgio-2.0.so.0.6000.6)
> | by 0x553F41D: g_application_run (in /usr/lib64/libgio-2.0.so.0.6000.6)
>
> Signed-off-by: Victor Toso <victortoso at redhat.com>
> ---
> src/remote-viewer.c | 18 ++++++++++--------
> 1 file changed, 10 insertions(+), 8 deletions(-)
>
> diff --git a/src/remote-viewer.c b/src/remote-viewer.c
> index 8938ef9..2818221 100644
> --- a/src/remote-viewer.c
> +++ b/src/remote-viewer.c
> @@ -396,7 +396,7 @@ virt_viewer_app_set_ovirt_foreign_menu(VirtViewerApp *app,
> }
>
> static gboolean
> -create_ovirt_session(VirtViewerApp *app, const char *uri, GError **err)
> +create_ovirt_session(VirtViewerApp *app, GError **err)
> {
> OvirtProxy *proxy = NULL;
> OvirtApi *api = NULL;
> @@ -421,9 +421,11 @@ create_ovirt_session(VirtViewerApp *app, const char *uri, GError **err)
> gchar *ticket = NULL;
> gchar *host_subject = NULL;
> gchar *guid = NULL;
> + gchar *guri = NULL;
>
> g_return_val_if_fail(VIRT_VIEWER_IS_APP(app), FALSE);
>
> + g_object_get(app, "guri", &guri, NULL);
> if (!parse_ovirt_uri(uri, &rest_uri, &vm_name, &username)) {
Patch does not build. Are you sure your configure passes the ovirt checks?
remote-viewer.c: In function 'create_ovirt_session':
remote-viewer.c:430:26: error: 'uri' undeclared (first use in this
function); did you mean 'guri'?
430 | if (!parse_ovirt_uri(uri, &rest_uri, &vm_name, &username)) {
| ^~~
| guri
remote-viewer.c:430:26: note: each undeclared identifier is reported
only once for each function it appears in
> g_set_error_literal(&error, VIRT_VIEWER_ERROR, VIRT_VIEWER_ERROR_FAILED,
> _("failed to parse ovirt uri"));
> @@ -561,6 +563,7 @@ create_ovirt_session(VirtViewerApp *app, const char *uri, GError **err)
> success = TRUE;
>
> error:
> + g_free(guri);
> g_free(username);
> g_free(rest_uri);
> g_free(vm_name);
> @@ -645,17 +648,16 @@ remote_viewer_recent_add(gchar *uri, const gchar *mime_type)
>
> static void
> remote_viewer_session_connected(VirtViewerSession *session,
> - gchar *guri)
> + VirtViewerApp *app)
> {
> gchar *uri = virt_viewer_session_get_uri(session);
> const gchar *mime = virt_viewer_session_mime_type(session);
>
> if (uri == NULL)
> - uri = g_strdup(guri);
> + g_object_get(app, "guri", &uri, NULL);
>
> remote_viewer_recent_add(uri, mime);
> g_free(uri);
> - g_free(guri);
> }
>
> static gchar *
> @@ -675,14 +677,14 @@ read_all_stdin(gsize *len, GError **err)
> }
>
> static gboolean
> -remote_viewer_initial_connect(RemoteViewer *self, const gchar *type, const gchar *guri,
> +remote_viewer_initial_connect(RemoteViewer *self, const gchar *type,
> VirtViewerFile *vvfile, GError **error)
> {
> VirtViewerApp *app = VIRT_VIEWER_APP(self);
>
> #ifdef HAVE_OVIRT
> if (g_strcmp0(type, "ovirt") == 0) {
> - if (!create_ovirt_session(app, guri, error)) {
> + if (!create_ovirt_session(app, error)) {
> g_prefix_error(error, _("Couldn't open oVirt session: "));
> return FALSE;
> }
> @@ -694,7 +696,7 @@ remote_viewer_initial_connect(RemoteViewer *self, const gchar *type, const gchar
> }
>
> g_signal_connect(virt_viewer_app_get_session(app), "session-connected",
> - G_CALLBACK(remote_viewer_session_connected), g_strdup(guri));
> + G_CALLBACK(remote_viewer_session_connected), app);
>
> virt_viewer_session_set_file(virt_viewer_app_get_session(app), vvfile);
> #ifdef HAVE_OVIRT
> @@ -787,7 +789,7 @@ retry_dialog:
> _("Cannot determine the connection type from URI"));
> goto cleanup;
> }
> - if (!remote_viewer_initial_connect(self, type, guri, vvfile, &error))
> + if (!remote_viewer_initial_connect(self, type, vvfile, &error))
> goto cleanup;
> }
>
>
--
Eduardo de Barros Lima (Etrunko)
Software Engineer - Red Hat
etrunko at redhat.com
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